Showing posts with label T-Rex. Show all posts

Friday, September 12, 2014

Spinosaurus fossil: 'Giant swimming dinosaur' unearthed

http://www.bbc.co.uk/news/

By Rebecca Morelle Science Correspondent, BBC News

Spinosaurus is thought to be the largest known carnivore and would have feasted on huge fish and sharks

A giant fossil, unearthed in the Sahara desert, has given scientists an unprecedented look at the largest-known carnivorous dinosaur: Spinosaurus.

The 95-million-year-old remains confirm a long-held theory: that this is the first-known swimming dinosaur.
Scientists say the beast had flat, paddle-like feet and nostrils on top of its crocodilian head that would allow it to submerge with ease.
The research is published in the journal Science.
Lead author Nizar Ibrahim, a palaeontologist from the University of Chicago, said: "It is a really bizarre dinosaur - there's no real blueprint for it.
"It has a long neck, a long trunk, a long tail, a 7ft (2m) sail on its back and a snout like a crocodile.
"And when we look at the body proportions, the animal was clearly not as agile on land as other dinosaurs were, so I think it spent a substantial amount of time in the water."

While other ancient creatures, such as the plesiosaur and mosasaur, lived in the water, they are marine reptiles rather than dinosaurs, making Spinosaurus the only-known semi-aquatic dinosaur.
Spinosaurus aegyptiacus remains were first discovered about 100 years ago in Egypt, and were moved to a museum in Munich, Germany.
However, they were destroyed during World War II, when an Allied bomb hit the building.
A few drawings of the fossil survived, but since then only fragments of Spinosaurus bones have been found.
The new fossil, though, which was extracted from the Kem Kem fossil beds in eastern Morocco by a private collector, has provided scientists with a more detailed look at the dinosaur.
"For the very first time, we can piece together the information we have from the drawings of the old skeleton, the fragments of bones, and now this new fossil, and reconstruct this dinosaur," said Dr Ibrahim.

The dinosaur has a number of anatomical features that suggest it was semi-aquatic

A life-size reconstruction of Spinosaurus is on display at the National Geographic Museum in Washington DC

The team says that Spinosaurus was a fearsome beast.
The researchers say that, at more than 15m (50ft) from nose to tail, it was potentially the largest of all the carnivorous dinosaurs - bigger even than the mighty Tyrannosaurus rex.
Scientists had long suspected that the giant could swim, but the new fossil offers yet more evidence for its semi-aquatic existence.
Dr Ibrahim explained: "The one thing we noticed was that the proportions were really bizarre. The hind limbs were shorter than in other predatory dinosaurs, the foot claws were quite wide and the feet almost paddle shaped.
"We thought: 'Wow - this looks looks like adaptations for a life mainly spent in water.'"
He added: "And then we noticed other things. The snout is very similar to that of fish-eating crocodiles, with interlocking cone-shaped teeth.
"And even the bones look more like those of aquatic animals than of other dinosaurs. They are very dense and that is something you see in animals like penguins or sea cows, and that is important for buoyancy in the water."
Its vast spiked dorsal sail, though, was probably more useful for attracting mates than aiding swimming.

The fossil was unearthed from the Kem Kem fossil beds in Morocco

The researchers say that Spinosaurus lived in a place they describe as "the river of giants", a waterway that stretched from Morocco to Egypt.
They believe it would have feasted on giant sharks and other car-sized fish called coelacanths and lungfish, competing with enormous crocodile-like creatures for its prey.
Commenting on the research, Prof Paul Barrett, from London's Natural History Museum, said: "The idea that Spinosaurus was aquatic has been around for some time and this adds some useful new evidence to address that issue.
"But finding a more complete skeleton after the best material was destroyed in a WW2 bombing raid is significant, and this has allowed some surprising things to be found out about this animal.
"One of the things about this paper that struck me as particularly neat was the suggestion that Spinosaurus was a quadruped - all other meat-eating dinosaurs were bipeds. It would have moved in a really freaky, weird way in comparison with its relatives - whether on land or in water.
"One issue though, due to the way it was obtained - through a private collector - is that it would be good to get confirmation, such as the original excavation map, to show that all of the parts definitely came from a single skeleton."

Monday, September 1, 2014

Could Dinosaurs Have Survived?

http://learningenglish.voanews.com/

The feathered dinosaur Microraptor pounces on a nest of primitive birds. Both species lived around 120 million years ago in what is now northern China. Credit: Brian Choo

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Dinosaurs last lived on Earth about 65 million years ago. For many years, scientists have debated how and why dinosaurs disappeared. But improved tools and records of fossil remains have led some experts to agree about the disappearance of these ancient creatures. We get more from Jeri Watson.
University of Edinburgh researcher Steve Brusatte led the team of experts. They blamed a huge rock from space – a 10-kilometer-wide asteroid -- for the dinosaurs’ disappearance. Their findings appeared in the journal Biological Reviews.
“The asteroid did it. But that asteroid probably hit at a particularly bad time.”
Steve Brusatte says the rocky object was responsible for environmental damage worldwide. He says the asteroid caused tsunami waves, earthquakes, wildfires, acid rain and sudden temperature changes.
Mr. Brusatte and his team proposed that if the asteroid had struck the Earth a few million years earlier, the dinosaurs might have been better able to survive. By the time the asteroid struck, dinosaurs had already lost some of their strength.
“A lot of the big plant eating dinosaurs, those horned dinosaurs like triceratops, the bottom of the food chain dinosaurs, the base of dinosaur ecosystems, those dinosaurs had declined a little bit in their diversity.”
He notes that dinosaur populations had grown and then decreased in number over 150 million years.
His team’s report appears in the journal Biological Reviews.
But some plants and animals DID survive through the period of dinosaur extinction. Another study looks at one group of dinosaurs that lived through the disasters. It shows how large cold-blooded, meat–eating animals like Tyrannosaurus Rex may have developed into small, warm-blooded birds.
Biologist Michael Lee works jointly with the South Australian Museum and the University of Adelaide. He was the lead writer of the study. He and his team centered their efforts on one group of dinosaur, meat-eating theropods. They examined 120 species.
One group of dinosaurs was evolving, changing four times as fast as all the other dinosaurs living during that period. And over time, the fast-evolving group became birds.
The scientists studied how those changes took place over 50 million years. They say that during that time, each generation got smaller and smaller. Michael Lee says that by the time the asteroid hit, the earliest birds had been living for about 100 million years.
“The bird ancestor started exploring a new kind of lifestyle which involved smaller body size, greater agility and greater ability to regulate their body heat using things like feathers and various other things.’
Mr. Lee said smaller body size was responsible for the changes. And that, in turn, it would have made way for changes in their body structure like the addition of wings and flight feathers. He also noted other changes seen in modern birds, such as wish bones.
About 10,000 species of birds now live on the planet.

This story was based on a report by VOA Correspondent Rosanne Skirble and adapted for Learning English by Jeri Watson. George Grow was the editor.

Friday, June 13, 2014

Warm or cold? Dinosaurs had 'in-between' blood

By Charles Q. Choi, Live Science Contributor

Published June 12, 2014

Comparative growth rates in vertebrates. Dinosau rs grew intermediate to endothermic mammals and birds and ectothermic reptiles and fi sh, but closest to living mesotherms.John Grady

Dinosaurs may not have been cold-blooded like modern reptiles or warm-blooded like mammals and birds instead, they may have dominated the planet for 135 million years with blood that ran neither hot nor cold, but was a kind of in-between that's rare nowadays, researchers say.
Modern reptiles such as lizards, snakes and turtles are cold-blooded or ectothermic, meaning their body temperatures depend on their environments. Birds and mammals, on the other hand, are warm-blooded, meaning they control their own body temperatures, attempting to keep them at a safe constant in the case of humans, at about 98.6 degrees Fahrenheit (37 degrees Celsius).
Dinosaurs are classified as reptiles, and so for many years scientists thought the beasts were cold-blooded, with slow metabolisms that forced them to lumber across the landscape. However, birds are modern-day dinosaurs and warm-blooded, with fast metabolic rates that give them active lifestyles, raising the question of whether or not their extinct dinosaur relatives were also warm-blooded. [Avian Ancestors: Dinosaurs That Learned to Fly (Images)]
Animal metabolism
To help solve this decades-old mystery, researchers developed a new method for analyzing the metabolism of extinct animals. They found "dinosaurs do not fit comfortably into either the cold-blooded or warm-blooded camp they genuinely explored a middle way," said lead study author John Grady, a theoretical ecologist at the University of New Mexico.
Scientists often seek to deduce the metabolisms of extinct animals by looking at the rates at which their bones grow. The method resembles cutting into a tree and looking at the thickness of the rings of wood within, which can reveal how well or poorly that tree grew any given year. Similarly, looking at the way bone is deposited in layers in fossils reveals how quickly or slowly that animal might have grown.
Grady and his colleagues not only looked at growth rings in fossils, but also sought to estimate their metabolic rates by looking at changes in body size as animals grew from birth to adults. The researchers looked at a broad spectrum of animals encompassing both extinct and living species, including cold- and warm-blooded creatures, as well as dinosaurs.
The scientists found growth rate to be a good indicator of metabolic rates in living animals, ranging from sharks to birds. In general, warm-blooded mammals that grow about 10 times faster than cold-blooded reptiles also metabolize about 10 times faster.
When the researchers examined how fast dinosaurs grew, they found that the animals resembled neither mammals nor modern reptiles, and were neither ectotherms nor endotherms. Instead, dinosaurs occupied a middle ground, making them so-called "mesotherms."
Modern mesotherms
Today, such energetically intermediate animals are uncommon, but they do exist. For instance, the great white shark, tuna and leatherback sea turtle are mesotherms, as is the echidna, an egg-laying mammal from Australia. Like mammals, mesotherms generate enough heat to keep their blood warmer than their environment, but like modern reptiles, they do not maintain a constant body temperature. [See Photos of Echidna and Other Bizarre Monotremes]
"For instance, tuna body temperature declines when they dive into deep, colder waters, but it always stays above the surrounding water," Grady told Live Science.
Body size may play a role in mesothermy, because larger animals can conserve heat more easily. "For instance, leatherback sea turtles are mesotherms, but smaller green sea turtles are not," Grady said. However, mesothermy does not depend just on large size. "Mako sharks are mesotherms, but whale sharks are regular ectotherms," Grady said.
Endotherms can boost their metabolisms to warm up "for instance, we shiver when cold, which generates heat," Grady said. "Mesotherms have adaptations to conserve heat, but they do not burn fat or shiver to warm up. Unlike us, they don't boost their metabolic rate to stay warm."
Some animals are what are known as gigantotherms, meaning they are just so massive that they maintain heat even though they do not actively control their body temperature.
"Gigantotherms like crocodiles rely on basking to heat up, so they are not mesotherms," Grady said. "Gigantotherms are slower to heat up and cool down, but if they rely on external heat sources like the sun, then they are not mesotherms. In general, mesotherms produce more heat than gigantotherms and have different mechanisms for conserving it."
Advantages of being a mesotherm
Mesothermy would have permitted dinosaurs to move, grow and reproduce faster than their cold-blooded reptilian relatives, making the dinosaurs more dangerous predators and more elusive prey. This may explain why dinosaurs dominated the world until their extinction about 65 million years ago, Grady suggested.
At the same time, dinosaurs' lower metabolic rates compared to mammals allowed them to get by on less food. This may have permitted the enormous bulk that many dinosaur species attained. "For instance, it is doubtful that a lion the size of T. rex would be able to eat enough wildebeests or elephants without starving to death," Grady said. "With their lower food demands, however, a real T. rex was able to get by just fine."
All in all, Grady suspected that where direct competition occurs, warm-blooded endotherms suppress mesotherms, mesotherms suppress active but cold-blooded ectotherms, and active ectotherms suppress more lethergic sit-and-wait ectotherms
Although mesothermy appears widespread among dinosaurs, not every dinosaur was necessarily a mesotherm, Grady said. "Dinosaurs were a big and diverse bunch, and some may have been endotherms or ectotherms," he said. "In particular, feathered dinosaurs are a bit of a mystery. What do you call a metabolically intermediate animal covered in feathers? Is it like the mesothermic echidna? Or just a low-power endotherm?"
The first bird, Archaeopteryx, "was more like a regular dinosaur than any living bird," Grady said. "It grew to maturity in about two years. In contrast, a similarly sized hawk grows in about six weeks, almost 20 times faster. Despite feathers and the ability to take flight, the first birds were not the active, hot-blooded fliers their descendants came to be."
These findings could help shed light on how warm-blooded animals such as humans evolved.
"The origins of endothermy in mammals and birds are unclear," Grady said. Studying the growth rates of the ancestors of birds and mammals "will shed light on these mysterious creatures."
The scientists detailed their findings in the June 13 issue of the journal Science.

Friday, May 9, 2014

No lie: dinosaur dubbed 'Pinocchio rex' would eat you alive

By By Will Dunham 14 hours ago

Two Qianzhousaurus sinensis individuals are pictured hunting in this undated handout artist's rendering. …

By Will Dunham

WASHINGTON (Reuters) - Its nickname may sound funny - "Pinocchio rex" - but it probably would not have been wise to laugh at this strange, long-snouted cousin of the famous meat-eating dinosaur T. rex as it easily could have eaten you alive.
Scientists on Wednesday identified a new member of Tyrannosaurus rex's family, a beast named Qianzhousaurus sinensis that was up to 30 feet (9 meters) long and stalked China at the very end of the age of dinosaurs.
It differs in some significant ways from other members of the carnivorous group of dinosaurs known as tyrannosaurs, especially with a skull far more elongated than that of T. rex.
"It's a new breed of tyrannosaur, with a long snout and lots of horns on its skull, very different from the short-snouted, robust, muscular skulls of T. rex. So it tells us that tyrannosaurs were more ecologically variable than we previously thought," said paleontologist Steve Brusatte of the University of Edinburgh in Scotland, one of the researchers.
Its elongated snout prompted researchers to nickname it "Pinocchio rex," inspired by the wooden puppet who dreamed of being a real boy but whose nose grew when he told a lie. "The long snout made us think of Pinocchio and his long nose, so Pinocchio rex seemed like a cheeky nickname," Brusatte said.
Two other tyrannosaur fossils with long snouts have been found previously in Mongolia but both specimens were juveniles. Brusatte said it had been unclear whether those two were dinosaur kiddies with juvenile features like a long snout that would disappear in adulthood.
"The new fossil solves this debate because it is twice the size of the two Mongolian specimens and much more mature, and still has the long snout and weird horns. So these were not juvenile features, but characteristic features of this unusual subgroup of long-snouted tyrannosaurs," Brusatte said.
Qianzhousaurus lived about 66 million years ago, not long before an asteroid believed to have been 6 miles wide (10 km) hit Earth and wiped out the dinosaurs and many other creatures.
"It would have been one of the last surviving dinosaurs and this species may have even witnessed the asteroid impact," said Brusatte, whose study appears in the journal Nature Communications.
Qianzhousaurus was smaller than T. rex, which lived at the same time in North America, measured about 40 feet (12 meters) long and was the largest known land predator ever. Even though it still had the "toothy grin" of T. rex, the unique snout of Qianzhousaurus and its more slender build suggested it favored different types of prey than "conventional" tyrannosaurs, the researchers said.
"It was still a big boy," Brusatte said. "And it still had a long mouthful of sharp teeth. You wouldn't want to run into it. It is something of a runt compared to T. rex, but T. rex was the baddest predator of all time."
The beautifully preserved fossil was found by workmen at a construction site in Jiangxi province in southern China.
Qianzhousaurus lived in a fairly wet, lush, rich landscape full of dinosaurs including feathered, bird-like ones named Banji, Ganzhousaurus, Jiangxisaurus and Nankangia that may have been on its menu as well as the huge, long-necked Gannansaurus.
"Although we are only starting to learn about them, the long-snouted tyrannosaurs were apparently one of the main groups of predatory dinosaurs in Asia," another of the researchers, paleontologist Junchang Lü of the Chinese Academy of Geological Sciences, said in a statement.
Its genus name, Qianzhousaurus, honors a nearby city. Its species name, sinensis, pays homage to China.
(Reporting by Will Dunham; Editing by James Dalgleish)

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Friday, March 21, 2014

'Chicken from hell' found who lived alongside T. rex

Scientists discovered nearly-complete remains of the bizarre dinosaur in the U.S.

By Reuters | Mar. 20, 2014 | 11:57 AM

This illustration provided by the Carnegie Museum of Natural History on March 18, 2014 shows the 'chicken from hell' dinosaur. Photo by AP

Reconstructed skull of the crested hell-chicken, otherwise known as the dinosaur Anzu wyliei. Photo by AP

A fossil Microraptor gui preserved with its feathers intact: The arrows point at some. Photo by Wikimedia Commons

Scientists find dinosaur that ate Jurassic Europe

By Reuters and Haaretz

Mar. 11, 2014 | 5:53 AM |

If you're a dinosaur with a nickname as funky as "the chicken from hell," you had better be able to back it up.
A dinosaur called Anzu wyliei that scientists identified on Wednesday from fossils found in North Dakota and South Dakota does just that. It had a head shaped like a bird's, a toothless beak, an odd crest on its cranium, hands with big sharp claws, long legs for fast running and was probably covered in feathers.
It is the largest North American example of a type of bird-like dinosaur well known from Asia. Its extensive remains offer a detailed picture of the North American branch of these dinosaurs that had remained mysterious since their first bones were found about a century ago, the scientists said.
What would someone think if they encountered this creature that lived 66 million years ago? "I don't know whether they would scream and run away, or laugh, because it is just an absurd-looking monster chicken," said University of Utah paleontologist Emma Schachner, one of the researchers.
Anzu wyliei measured over 3 meters long, 1.5 meters tall at the hip and weighed about 200 to 300 kg, the researchers said.
"It has the nickname 'the chicken from hell.' And that's a pretty good description," said paleontologist Matt Lamanna of the Carnegie Museum of Natural History in Pittsburgh, who led the research published in the journal PLOS ONE.
"If you could get in a time machine and go back to Western North America at the end of the age of dinosaurs and see this thing, I would say your first reaction might be, 'What a weird looking bird,'" Lamanna added. "It would not look like most people's conception of a dinosaur."
Scientists think birds arose much earlier from small feathered dinosaurs. The earliest known bird is 150 million years old. This dinosaur's bird-like traits included a beak, hollow leg bones and air spaces in its backbone, paleontologist said Hans-Dieter Sues of the Smithsonian Institution's National Museum of Natural History.
Its bizarre head crest resembled that of the cassowary, a flightless bird native to Australia and New Guinea.
Fossils of feathers are extremely rare and they were not found with any of the three partial skeletons of Anzu wyliei. But the researchers believe it had feathers based on fossils of close relatives from China that have clear evidence of them.
Asian cousins
It closely resembles its Asian cousins like Oviraptor, whose fossils have been found brooding over a clutch of its eggs in a bird-like manner. The Asian part of the family includes many well-preserved examples, from ones as small as a turkey to one even bigger than Anzu wyliei. The North American branch until now had been represented by largely fragmentary remains.
Anzu wyliei lived at the sunset of the age of dinosaurs, not long before an enormous meteorite is thought to have struck Earth about 65.5 million years ago and wiped them out along with hordes of other creatures, while sparing many birds.
It lived in a humid, warm, low-lying environment dotted with rivers and swamps that may have looked like the Louisiana bayou. It was lush with vegetation and plant-eating dinosaurs like the horned Triceratops, armored Ankylosaurus, dome-headed Pachycephalosaurus and duck-billed Edmontosaurus.
But also hanging around the neighborhood was one of the fiercest predators in Earth's history, Tyrannosaurus rex.
Anzu wyliei may have been an omnivore, munching on leaves, fruits or flowers while also swallowing the occasional mammal foolish enough to cross its path, the researchers said.
It probably needed to be careful not to end up on someone else's menu. "To a T. rex, this thing would not look like a 'chicken from hell.' It would look like lunch," Lamanna said.
Its genus name, Anzu, is named after a feathered demon in Sumerian mythology. Its species name, wyliei, honors the grandson of a trustee of the Carnegie museum in Pittsburgh where the lead researcher works.
The three sets of bones - which together included almost all parts of the skeleton - come from a region famed for dinosaur remains known as the Hell Creek Formation of the Dakotas and Montana. Two of the three sets of remains had partially healed injuries, perhaps the remnants of a couple of dinosaur tussles.

Thursday, March 13, 2014

Pint-sized tyrannosaur was king of the Arctic

By Kerry Sheridan 9 hours ago

Washington (AFP) - A pint-sized tyrannosaur braved the frigid Arctic and feasted on fellow dinosaurs 70 million years ago, according to a report Wednesday on a new species identified from fossilized skull bones in Alaska.

Scientists have crowned the fierce creature the "polar bear lizard," or Nanuqsaurus hoglundi, and they say it stood as tall as a modern man but was half the size of its very close cousin, T. rex, the "lizard king."

An analysis of several skull bones and teeth are described in the journal PLoS ONE by Anthony Fiorillo and Ronald Tykoski of the Perot Museum of Nature and Science in Texas.

Roving across land that was dark for half the year and prone to rainy, snowy and frigid spells, the miniature tyrannosaur likely had a strong sense of smell and may also have had sharp vision to hunt prey at night.
It was also just as big as another common meat-eating dinosaur found in Alaska, the Troodon, Fiorillo told AFP.
"To us that is a really cool thing because it is telling us, we think, that there is something about the Arctic environment of 70 million years ago that selected for an optimal body size for a successful predator."
- Skull fragments tell a story -
The bones were found on a bluff above the Colville River in northern Alaska.

Remains of the much larger T. rex have typically been found further south, scattered across the western United States where the climate would have been warmer.

The area inside the Arctic Circle where the dinosaur bones were found was not as cold 70 million years ago, and was probably on par with modern day Seattle, Washington, or Calgary, Canada.

The tyrannosaur's skull fragments were found in a hole along with a horned dinosaur it likely killed and tried to eat, based on the tooth-size gashes in the plant-eater's bones, researchers said.

At the time of publication, researchers had four bone pieces, some of which were crucial because they showed the head growth of an adult, rather than a juvenile, and allowed scientists to estimate the overall skull size.

Since then, more fragments have been unearthed, Fiorillo said.

"We have a pretty complete picture of the skull roof now. The beauty of that is that the sediment that filled it in preserves the shape of the brain and we can see that this animal also had a well developed sense of smell."

University of Chicago paleontologist Paul Sereno, who was not involved in the research, described the jaw and skull fragments as "pretty exciting."

When fossils of dinosaurs were first found in the Arctic three decades ago, they were initially mistaken for whale bones.

Early on, some experts believed the dinosaurs may have migrated, or that juveniles would have been unable to survive there, but more recent discoveries have debunked those ideas.

"We couldn't get ourselves to believe that they lived up there in the darkness," Sereno told AFP, adding that recent discoveries have changed that way of thinking.

"They must have been managing somehow. We know that reindeer change their diet to eat all sorts of strange things."

The new species' name, Nanuqsaurus hoglundi, is a nod to the Inuit name for polar bear, Nanook, and the natural gas tycoon Forrest Hoglund who helped fund the Texas museum where Arctic dinosaur bones are displayed

Thursday, November 7, 2013

'King of gore' dino is T. rex's oldest known cousin

16 hours ago

A paleontologist prepares and assembles the fossils Tyrannosaurus rex in Los Angeles on March 27, 2008 (AFP Photo/Gabriel Bouys)

Washington (AFP) - A new species of tyrannosaur has been unearthed in Utah, with skull bones showing an 80 million-year-old beast that is the oldest known cousin of the legendary T. rex.

The meat-eating Lythronax argestes, which means "king of gore," had wide-set eyes that helped it track prey and a load of teeth packed into a more slender snout than the T. rex's, researchers said in the journal PLoS ONE.
The Lythronax was among the lighter, more compactly built tyrannosaurids, and may have been about half as heavy as the largest T. rex.
The beast weighed about 2.5 tonnes and was 24 feet long (eight meters), said the research team led by Mark Loewen, adjunct assistant professor in the Department of Geology and Geophysics at the University of Utah.
Its bones -- including parts of the skull, hips, leg and tail -- were found in the Wahweap Formation within the Grand Staircase-Escalante National Monument in south-central Utah.
"The width of the back of the skull of Lythronax allowed it to see with an overlapping field of view—giving it the binocular vision— very useful for a predator and a condition we associate with T. rex," said Loewen.
It was also as older -- T. rex roamed the Earth about 10-12 million years later, researchers said.
Tyrannosaurids ran upright on two legs and had short arms, and were renowned for attacking other dinosaurs as well as scavenging the carcasses of dead animals for food.
Researchers said they likely originated in northern Laramidia, then a swampy and humid island which is now western North America.
Several species likely moved south over time, while others made their way toward Asia 70-75 million years ago.

New dinosaur that predates T. rex found in Utah

Yahoo News

By BRADY McCOMBS 9 hours ago

SALT LAKE CITY (AP) — Paleontologists on Wednesday unveiled a new dinosaur discovered four years ago in southern Utah that proves giant tyrant dinosaurs like the Tyrannosaurus rex were around 10 million years earlier than previously believed.

A full skeletal replica of the carnivore — the equivalent of the great uncle of the T. rex — was on display at the Natural History Museum of Utah alongside a 3-D model of the head and a large painted mural of the dinosaur roaming a shoreline.
It was the public's first glimpse at the new species, which researchers named Lythronax argestes (LY'-throw-nax ar-GES'-tees). The first part of the name means "king of gore," and the second part is derived from poet Homer's southwest wind.
The fossils were found in the Grand Staircase-Escalante National Monument in November 2009, and a team of paleontologists spent the past four years digging them up and traveling the world to confirm they were a new species.
Paleontologists believe the dinosaur lived 80 million years ago in the late Cretaceous Period on a landmass in the flooded central region of North America.
The discovery offers valuable new insight into the evolution of the ferocious tyrannosaurs that have been made famous in movies and captured the awe of school children and adults alike, said Thomas Holtz Jr., a vertebrate paleontologist at the University of Maryland department of geology.
"This shows that these big, banana-tooth bruisers go back to the very first days of the giant tyrant dinosaurs," said Holtz, who reviewed the findings. "This one is the first example of these kind of dinosaurs being the ruler of the land."
The new dinosaur likely was a bit smaller than the Tyrannosaurus rex but was otherwise similar, said Mark Loewen, a University of Utah paleontologist who co-authored a journal article about the discovery with fellow University of Utah paleontologist Randall Irmis.
It was 24 feet long and 8 feet tall at the hip, and was covered in scales and feathers, Loewen said. Asked what the carnivorous dinosaur ate, Loewen responded: "Whatever it wants."
"That skull is designed for grabbing something, shaking it to death and tearing it apart," he said.
The fossils were found by a seasonal paleontologist technician for the Bureau of Land Management who climbed up two cliffs and stopped at the base of a third in the national monument.
"I realized I was standing with bone all around me," said Scott Richardson, who called his boss, Alan Titus, to let him know about the fossils.
Loewen and others spent three years traveling the world to compare the fossils to other dinosaurs to be absolutely sure it was a new species. The findings are being published in the journal PLOS One.
The fossils were found in a southern Utah rock formation that also has produced the oldest-known triceratops, named "Diabloceratops," and other dome-headed and armored dinosaurs.
There are about 1 million acres of cretaceous rocks that could be holding other new species of dinosaurs, said Titus, the BLM paleontologist who oversees the Grand Staircase-Escalante National Monument. Only about 10 percent of the rock formation has been scoured, he said. Twelve other new dinosaurs found there are waiting to be named.
"We are just getting started," Titus said. "We have a really big sandbox to play in."
Holtz said the finding is a testament to the bounty of fossils lying in the earth in North America. He predicts more discoveries in Utah.
"It shows we don't have to go to Egypt or Mongolia or China to find new dinosaurs," Holtz said. "It's just a matter of getting the field teams out."
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